llvm-project.git/llvm/lib/CodeGen/MachineFunctionSplitter.cpp, branch main Unnamed repository; edit this file 'description' to name the repository. [CodeGen] Add skipFunction() check to MachineFunctionSplitter (#166260) 2025-11-04T19:01:50+00:00 Grigory Pastukhov 99913765+grigorypas@users.noreply.github.com 2025-11-04T19:01:50+00:00 7398591148f4351b38404304d8e2acb80651aaf3 MachineFunctionSplitter was missing a skipFunction() check, causing it to incorrectly split functions that should be skipped (e.g., functions with optnone attribute). This patch adds an early skipFunction() check in runOnMachineFunction() to ensure these functions are never split, regardless of profile data availability or other splitting conditions. 
MachineFunctionSplitter was missing a skipFunction() check, causing it
to incorrectly split functions that should be skipped (e.g., functions
with optnone attribute).

This patch adds an early skipFunction() check in runOnMachineFunction()
to ensure these functions are never split, regardless of profile data
availability or other splitting conditions.
 [BasicBlockSections] Allow mixing of -basic-block-sections with MFS. (#117076) 2024-11-23T06:23:29+00:00 Rahman Lavaee rahmanl@google.com 2024-11-23T06:23:29+00:00 68f7b075c07197803625431ba92c337af7470c85 This PR allows mixing `-basic-block-sections` with `-enable-machine-function-splitter`. The strategy is to let `-basic-block-sections` take precedence over functions with profiles. 
This PR allows mixing `-basic-block-sections` with
`-enable-machine-function-splitter`. The strategy is to let
`-basic-block-sections` take precedence over functions with profiles.
 [CodeGen] Remove unused includes (NFC) (#115996) 2024-11-13T07:15:06+00:00 Kazu Hirata kazu@google.com 2024-11-13T07:15:06+00:00 735ab61ac828bd61398e6847d60e308fdf2b54ec Identified with misc-include-cleaner. 
Identified with misc-include-cleaner.
 [CodeGen][NewPM] Port `machine-block-freq` to new pass manager (#98317) 2024-07-12T07:45:01+00:00 paperchalice liujunchang97@outlook.com 2024-07-12T07:45:01+00:00 099899961c1e89a1789f534579d35a74a2ef1dda - Add `MachineBlockFrequencyAnalysis`. - Add `MachineBlockFrequencyPrinterPass`. - Use `MachineBlockFrequencyInfoWrapperPass` in legacy pass manager. - `LazyMachineBlockFrequencyInfo::print` is empty, drop it due to new pass manager migration. 
- Add `MachineBlockFrequencyAnalysis`.
- Add `MachineBlockFrequencyPrinterPass`.
- Use `MachineBlockFrequencyInfoWrapperPass` in legacy pass manager.
- `LazyMachineBlockFrequencyInfo::print` is empty, drop it due to new
pass manager migration.
 [CodeGen] Clean up MachineFunctionSplitter MBB safety checking (NFC) 2024-02-22T17:36:08+00:00 Daniel Hoekwater hoekwater@google.com 2024-02-22T03:30:28+00:00 163eaf3bbc24e46a6ec9b71deda8c66f0354d2d7 Move the "is MBB safe to split" check out of `isColdBlock` and update the comment since we're no longer using a temporary hack. 
Move the "is MBB safe to split" check out of `isColdBlock` and update
the comment since we're no longer using a temporary hack.
[CodeGen][AArch64] Don't split jump table basic blocks 2023-08-28T21:47:57+00:00 Daniel Hoekwater hoekwater@google.com 2023-08-04T01:16:07+00:00 ef1c25eb50502692f343e9ac0b83b52086aa584e Jump tables on AArch64 are label-relative rather than table-relative, so having jump table destinations that are in different sections causes problems with relocation. Jump table lookups have a max range of 1MB, so all destinations must be in the same section as the lookup code. Both of these restrictions can be mitigated with some careful and complex logic, but doing so doesn't gain a huge performance benefit. Efficiently ensuring jump tables are correct and can be compressed on AArch64 is a TODO item. In the meantime, don't split blocks that can cause problems. Differential Revision: https://reviews.llvm.org/D157124 
Jump tables on AArch64 are label-relative rather than table-relative, so
having jump table destinations that are in different sections causes
problems with relocation. Jump table lookups have a max range of 1MB, so
all destinations must be in the same section as the lookup code. Both of
these restrictions can be mitigated with some careful and complex logic,
but doing so doesn't gain a huge performance benefit.

Efficiently ensuring jump tables are correct and can be compressed on
AArch64 is a TODO item. In the meantime, don't split blocks that can
cause problems.

Differential Revision: https://reviews.llvm.org/D157124
[CodeGen] Remove unused option in MachineFunctionSplitter. 2023-08-25T21:24:28+00:00 Snehasish Kumar snehasishk@google.com 2023-08-25T20:24:53+00:00 3dbabeadd63ebcf714a18c6fc783ab20de8eaa82 The option was added in github.com/llvm/llvm-project/commit/90ab85a but it doesn't seem to be used. The triple check has been removed so this shouldn't be required going forward. Reviewed By: MaskRay Differential Revision: https://reviews.llvm.org/D158885 
The option was added in github.com/llvm/llvm-project/commit/90ab85a but it doesn't seem to be used. The triple check has been removed so this shouldn't be required going forward.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D158885
[CodeGen][AArch64] Don't split functions with a red zone on AArch64 2023-08-24T21:57:35+00:00 Daniel Hoekwater hoekwater@google.com 2023-08-04T18:58:55+00:00 8c249c44d41f69c867fcf47f65e4646b626368d7 Because unconditional branch relaxation on AArch64 grows the stack to spill a register, splitting a function would cause the red zone to be overwritten. Explicitly disable MFS for such functions. Differential Revision: https://reviews.llvm.org/D157127 
Because unconditional branch relaxation on AArch64 grows the stack to
spill a register, splitting a function would cause the red zone to be
overwritten. Explicitly disable MFS for such functions.

Differential Revision: https://reviews.llvm.org/D157127
Reland "[CodeGen][AArch64] Make MFS testable on AArch64" 2023-08-22T20:21:33+00:00 Daniel Hoekwater hoekwater@google.com 2023-08-09T23:44:05+00:00 90ab85a1b2e72f63039fadf6669b23f52192defd Reverted by 3d22dac6c3b97d7bb92f243886dfb0d32a5c42e9 because it depended on b9d079d6188b50730e0a67267b7fee36008435ce, which broke some tests. 
Reverted by 3d22dac6c3b97d7bb92f243886dfb0d32a5c42e9 because it depended
on b9d079d6188b50730e0a67267b7fee36008435ce, which broke some tests.
Revert D157750 "[Driver][CodeGen] Properly handle -fsplit-machine-functions for fatbinary compilation." 2023-08-21T20:54:15+00:00 Fangrui Song i@maskray.me 2023-08-21T20:54:15+00:00 77596e6b167bf0a5efa790597d6b75ac5e685b55 This reverts commit 317a0fe5bd7113c0ac9d30b2de58ca409e5ff754. This reverts commit 30c4b97aec60895a6905816670f493cdd1d7c546. See post-commit discussions on https://reviews.llvm.org/D157750 that we should use a different mechanism to handle the error with --cuda-gpu-arch= The IR/DiagnosticInfo.cpp, warn_drv_for_elf_only, codegne tests in clang/test/Driver, and the following driver behavior (downgrading error to warning) changes are undesired. ``` % clang --target=riscv64 -fsplit-machine-functions -c a.c warning: -fsplit-machine-functions is not valid for riscv64 [-Wbackend-plugin] ``` 
This reverts commit 317a0fe5bd7113c0ac9d30b2de58ca409e5ff754.
This reverts commit 30c4b97aec60895a6905816670f493cdd1d7c546.

See post-commit discussions on https://reviews.llvm.org/D157750 that
we should use a different mechanism to handle the error with --cuda-gpu-arch=

The IR/DiagnosticInfo.cpp, warn_drv_for_elf_only, codegne tests in
clang/test/Driver, and the following driver behavior (downgrading error
to warning) changes are undesired.
```
% clang --target=riscv64 -fsplit-machine-functions -c a.c
warning: -fsplit-machine-functions is not valid for riscv64 [-Wbackend-plugin]
```